Semiconductor device

• US 20080203568A1
• Filed: 02/04/2008
• Published: 08/28/2008
• Est. Priority Date: 02/20/2007
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Inventors: Takahashi, Kouhei, Okabe, Seiji, Tanaka, Takekazu
• Granted Patent: US 7,791,198 B2
• Time in Patent Office: Days
• US Class Current: 257/738
• CPC Class Codes: H01L 2224/02166 Collar structures
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05082 Two-layer arrangements
• CPC Class Codes: H01L 2224/05166 Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05647 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/43848 Thermal treatments, e.g. annealing, controlled cooling
• CPC Class Codes: H01L 2224/45014 Ribbon connectors, e.g. rectangular cross-section
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48453 of the interface with the bonding area
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/48507 comprising an intermetallic compound
• CPC Class Codes: H01L 2224/48624 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48647 : Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48724 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48747 : Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48824 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48847 : Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2224/85205 : Ultrasonic bonding
• CPC Class Codes: H01L 23/4952 : the additional leads being a bump or a wire
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 24/45 : of an individual wire connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/85 : using a wire connector wire bonding in general B23K20/004
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00011 : Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/00015 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/01004 : Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01007 : Nitrogen [N]
• CPC Class Codes: H01L 2924/01012 : Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01051 : Antimony [Sb]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/01203 : 3N purity grades, i.e. 99.9%
• CPC Class Codes: H01L 2924/013 : Alloys
• CPC Class Codes: H01L 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/1306 : Field-effect transistor [FET]
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/2075 : larger or equal to 1 micron less than 10 microns
• CPC Class Codes: H01L 2924/20754 : larger or equal to 40 microns less than 50 microns
• CPC Class Codes: H01L 2924/20755 : larger or equal to 50 microns less than 60 microns

Abstract

An improved reliability in a region of a junction between a bonding wire and an electrode pad at higher temperature is achieved. A semiconductor device 100 includes a semiconductor chip 102, AlCu pads 107, which are provided in the semiconductor chip 102 and which contain Al as a major constituent and additionally contain copper (Cu), and CuP wires 111, which function as coupling members for connecting inner leads 117 provided outside of the semiconductor chip 102 with the semiconductor chip 102, and primarily contain Cu. The AlCu pads 107 and the CuP wires 111 are encapsulated with an encapsulating resin 115 that contains substantially no halogen.

Claims

1. A semiconductor device, comprising:

a semiconductor chip;

an electrode pad, provided in said semiconductor chip, and containing aluminum (Al) as a major constituent and additionally containing copper (Cu); and

a coupling member, connecting a coupling terminal provided outside of the semiconductor chip with said semiconductor chip, and primarily containing Cu,

wherein a plurality of layers of Cu and Al alloys having different content ratio of Cu and Al are provided in a region for coupling said coupling member with said electrode pad,

wherein said layers of Cu and Al alloys includes a copper-aluminum alloy (CuAl₂) layer and a layer provided between said CuAl₂ layer and said coupling member and having an Al content ratio that is relatively lower than that of said CuAl₂ layer, and

wherein said electrode pad and said coupling member are encapsulated with an encapsulating resin that contains substantially no halogen.

2. The semiconductor device as set forth in claim 1, wherein said layer provided between said CuAl₂ layer and said coupling member includes a copper-aluminum alloy (CuAl) layer having a content ratio of Cu and Al of 1:

1 and a layer provided between said CuAl layer and said coupling member and having an Al content ratio that is relatively lower than that of said CuAl layer.

3. The semiconductor device as set forth in claim 1, wherein a content ratio of Al over the whole said electrode pad is 50.0% wt. or higher and 99.9% wt. or lower, and a content ratio of Cu over the whole said electrode pad is 0.1% wt. or higher and 5.0% wt. or lower.

4. The semiconductor device as set forth in claim 1, wherein said electrode pad further contains silicon (Si).

5. The semiconductor device as set forth in claim 1, wherein said coupling member further contains phosphorus (P).

6. The semiconductor device as set forth in claim 1, wherein a resin in said encapsulating resin is composed of a polymer compound having substantially no bromine (Br) group in molecular backbone.

7. The semiconductor device as set forth in claim 1, wherein said encapsulating resin contains a metal hydrate.

8. The semiconductor device as set forth in claim 1, wherein a thickness of said electrode pad in a region where said coupling member is coupled is equal to or larger than ¼

of a thickness of said electrode pad in a region where said coupling member is not coupled.

9. The semiconductor device as set forth in claim 1, wherein said coupling member is a wire,

wherein a ball is formed in a junction of said wire with said electrode pad, and

wherein said ball is provided with a shoulder having an increased thickness of the ball from the center toward the outer periphery of the ball in cross-sectional view.

10. The semiconductor device as set forth in claim 2, wherein a content ratio of Al over the whole said electrode pad is 50.0% wt. or higher and 99.9% wt. or lower, and a content ratio of Cu over the whole said electrode pad is 0.1% wt. or higher and 5.0% wt. or lower.

11. The semiconductor device as set forth in claim 2, wherein a resin in said encapsulating resin is composed of a polymer compound having substantially no bromine (Br) group in molecular backbone.

12. The semiconductor device as set forth in claim 3, wherein a resin in said encapsulating resin is composed of a polymer compound having substantially no bromine (Br) group in molecular backbone.

13. The semiconductor device as set forth in claim 10, wherein a resin in said encapsulating resin is composed of a polymer compound having substantially no bromine (Br) group in molecular backbone.

14. The semiconductor device as set forth in claim 6, wherein said encapsulating resin contains a metal hydrate.

15. The semiconductor device as set forth in claim 11, wherein said encapsulating resin contains a metal hydrate.

16. The semiconductor device as set forth in claim 12, wherein said encapsulating resin contains a metal hydrate.

17. The semiconductor device as set forth in claim 13, wherein said encapsulating resin contains a metal hydrate.

18. The semiconductor device as set forth in claim 2, wherein a thickness of said electrode pad in a region where said coupling member is coupled is equal to or larger than ¼

of a thickness of said electrode pad in a region where said coupling member is not coupled.

19. The semiconductor device as set forth in claim 3, wherein a thickness of said electrode pad in a region where said coupling member is coupled is equal to or larger than ¼

of a thickness of said electrode pad in a region where said coupling member is not coupled.

20. The semiconductor device as set forth in claim 10, wherein a thickness of said electrode pad in a region where said coupling member is coupled is equal to or larger than ¼

of a thickness of said electrode pad in a region where said coupling member is not coupled.